SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3127703abaed688792daab4c841348a8ab357021c2f5eb1a661379449d43f9ea' 
  AND token = 'dzXOCCwW3W7grj16y7qYMZQTGdmJi4FmipgQrClriyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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