SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37484a10b9d599e5a3636c65970f9f44f58ba5dc5c7cec2a1947d07bcf067dba' 
  AND token = 'n3DTsWZXzFwZUK5AJ7AUZjWBKn7InzyDKnxU6gfgQ/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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