SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d4445916ad986bf061eb4bf6f7e256f8ed10a0864566d0f7f98e08a7ac8baf8' 
  AND token = 'LUl9mYb1hPf2g+S3Mmq+JK+iMlnQWdKlI6y/JJXUz+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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