SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bf40623890539d23d94988161d13a75c163860e0a7e0645e2d2eafd5c3899f68' 
  AND token = 'MKOJIP+OUK+cyRCVTv0J1lwiXcwRTq/WGuHCUX8fra0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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