SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8928ef157beae36a12837df2ea9c9cd4580090a37fd4750dadcd189dd945097' 
  AND token = 'Bn8wtHHR9FBcIyenQcDbN2wFeBjkUsn2r7cBWw92e3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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