SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8012ee44f0b7a5c9a42df4e73ae898b5d4fb4abf3de0f2b09c2c54795c1a725' 
  AND token = 'I6mrNohUcyBxW+g59Gu0JgjzrspcsJnvjP6PQVs7C/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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