SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '58b893a9f85880e57bb062bbf7cf78ad27c5c31bc25f35f10d1fd493cf357788' 
  AND token = 'M7nmQ3JJDKKlObSJ+zK40EIKsH2jpH6gPxUOBfUtudA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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