SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c38224b4a99b3da5f6d754648705db06abacadf080d609d705b9a0703b38693a' 
  AND token = 'SjCKxi+iDZ+MC0e64uajIr/+V281IISSEa/PUaE8/eg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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