SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9635a8bb7baddebebd430d311ae3464338be09f6ed326bdadc05429bc1a1e165' 
  AND token = 'o6vh27cBrkUz38bJhhABBJPYHJUcXJr/UA6vvsDxN1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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