SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc377251a6d6a5af5f4c481cc68f485fe966151a73b1b8843c33b44aff43ae66' 
  AND token = 'sWNnDGFvmm8wY9jdLPwJyfs2UXaOGc4YPgS3qYCfPY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}