SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8fb1fd9c2cb5046770c82cd50c3681e79898cead83ba07af115936f0a5d4fe0' 
  AND token = '6ORhVsjwq/WqhsWtz90sTFCnzaTFibrZHEAbkJu0CvY=' 
  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"
    }
  }
}