SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2f3f3c1788eba720cdaa9e8a3e543bc558ac29792c2fc70b1575372567daffbc' 
  AND token = 'tWCTaZJd/z0vo8O3C94rkBysZmJ72DDd6o76DK0ge+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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