SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dc68a1521fa0e1699431c61b061aab4d8a06c2866ad61f65e53ee374ba478299' 
  AND token = 'ut40AgH6xgCymJ8VG03X49Pm3f0XhGsF+IoLnqxUtz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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