SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e674063c214436be3c851aed1818dcf760d2f5cb31673b4de5fb39ba0012be98' 
  AND token = 'GYo9+fYsXN0Fc+6Iw6MAJI6vzth3zokuheNsxDKk3GU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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