SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77d4570468b43cc51097429e9b1127be2263a01b80a64b12a19a5f23aee77b61' 
  AND token = 'IIrqBUP1ehgVmskkoz0OZgnEdj+Jm9jmOKV7+0MdxpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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