SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c6eb8413658bf87db4d42ae283b790600dd62d2f404b3a4e510b8721e8bd006b' 
  AND token = 'pMb6zwZxYJb0MsDqvTzMGGVFHk5hhijzDrYIJOV78CA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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