SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '337698e71d6ee4500f04efac4c51e24792abe7ea6afdc1381efb20600158d898' 
  AND token = '4miCldLLuYTUBjyYq7hsS52wWZWcd474DxvaUvAovrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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