SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '972731da2e83318420ce16d6cab86e0939231926a08772b741d2737fb4f554b4' 
  AND token = 'NdoySwCX+2PBBLBDR4Tl+4/AK6butVVZ7v4FwieYnX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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