SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be6c874781c5225cb48bb9ec35d198f411140741eef1481514969f93a543ab91' 
  AND token = 'Rf1XMupfetrWNdIBeHvXMJd347PtmX+/+HNmA0sUmqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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