SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9947a846a245509cf1b1d42178e76ff087fe3e97285cc0b0cb858d1443099f58' 
  AND token = '3OL4AcaD60s/doY+x7j60qrqz9+VeeFXYJboy7um7aU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}