SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39d715402e15722214cf65165a40bf48caa826386ed261b7aa68a0c75247c183' 
  AND token = 'Ne0TwkmbTBjnxqzyB3NoKRrdYFZwt637IluAxoGUa88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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