SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e88cf3fbf0839423e0ecc6a6597c5ace5b4a543322b52e976a5f97ea963ce586' 
  AND token = 'Ta5TIKThxK3JP1Ofi44oW4lubkO8ZzoSip5zCrS3uhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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