SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9e284250bdef57ca8edf490fa861aa84959cce58f616b20acb01250a2fe3feb' 
  AND token = 'EfbMaPhdHNlO4jkjg8J1Ru3A3GMCD6m0KO4ckTZ+uVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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