SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9deba35137652a847f07dc35e1766b5bc24ccf0d7de7c55f3c3f73f075c0e72f' 
  AND token = '4jQstmyP667ojg+L5Z28Z0fyAWS7cru/6UseXFfREdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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