SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1e45ef4b92fc77e352af35244566f04053bd81e978460d07f93f06e3ab67135' 
  AND token = 'KJTfdjlBvUcyq3SijZQ+fkalzCuzGmtQyTJrCIp3tKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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