SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5461c81453d6a580080c01d20eaf2b703ff349f9b4bad704b0ac914dbc3394a6' 
  AND token = '/IHcah0L9jLkuzJIH1BP/RUr+LZPyp3vqVXGLQ6eWt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}