SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d2261b550bd483df7bca6e5bbeba8d7cf41879c37dd3dd297955b7dcd9871c7' 
  AND token = 'KW7yTO5bcPIWXvFDcsZiBmbu3u6FBpwOt/8Ei9xHdoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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