SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a402db6ab1e5f93d2d32265fd5865cd42e14ea1f9a9c125fe677f632c359f9b' 
  AND token = 'QMfeiP8qHPRnuhWOoMY+/YHN9aocjc0I5QGetgs+Hp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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