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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '51a049a51f825228660867a3a99f86f55ebf91423394314fa408a9e47b713b4c' 
  AND token = 'evqSOOnRFxmc70P9fE/7aXOJ48H7FgZdqL9lB+SnH00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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