SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03737098ff090d06aa25b097fc2ca88594d596797b9284f7d23025404b529dce' 
  AND token = 'GOPuh+OL/K3mPU6GvK5KxNKvK1GZC4xNkLDzdjJ8q80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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