SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dcaa9388c6b458b3f88b6235182706fd3f3c37408317456d4e8fc6829979910' 
  AND token = 'BLnM9X/HoheCiNPhS5Nfe8IVbfpKLv+pGJRzpKwZgig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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