SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ffb5aad288fb581177aa0aef3ac136ca81b0f0d1a015da870b65730255cbf219' 
  AND token = 'hM9luFmODZrjS2quet1aqyB4Yryn2QPNcfRA6JU5Iug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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