SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2d402fff10f54e21b5ff8d07e68b9fd0269c739dd0ee02723939d6267bcdbf38' 
  AND token = '0QxIyJPgH66mR+hSWU8kk8OvTzs+rI7/I6Sip+NVjIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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