SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f79522b19b78d19872fe9ffdb9e95c2471f894a28c6d141ea358256ca705f68c' 
  AND token = 'a4KEQ2bieribCVRpdU0ZlARELpAJIfT4bP1eBgO1lsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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