SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a54207980a944a4f72615e768e9da8b50a6ead3e0fdc7940ab51a9dcaf9fb222' 
  AND token = 'xFXZiAaYpNdCwT2ir4d8s18lgiK3imMOkxqa8Fq2HMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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