SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bca242d457428ffb793e24408fc4047c5563f571a8bd830e197c40d11456f8f4' 
  AND token = '5Jg5NUbtEz9u0dECKXAif1qhfQI8SdyMlCvfaT31mZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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