SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a556566df00f1359b52b01a7ad3efa69e02131774b78a2455619d3598f8b4972' 
  AND token = 'pUTIFJPyBZV+2Q/aaQTUX/9fg0Lc471vyNYJxnsB9pQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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