SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59f5fff33d04201dabc61563ea965c30350c739327162c26f01f2612b45593b9' 
  AND token = 'qhD6pMF4AYjDoydVgZhR7xOeVhP+q9abJgNlNBSW8Bs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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