SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccf5f5920740278c9d0f87f1c2be28b4bb84b5ef0a39167cf7cdf83e8eefaf84' 
  AND token = 'kFJzIWwSP3W8o1/d4PApalme7124EIuKPevhHjxhVyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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