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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd967018d31c762e23d68b8e609b7275f87576c0fbf63937c4b7985531b9a76a9' 
  AND token = 'lrvq//nPTuS6scijBjv5xaiKUXbSliexd3SKlJ97reU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}