SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a54424bb6aeff7d40b2f8aa614844386fb058e1b76b330995b63cb7fe73a5128' 
  AND token = 'urSVxJra7P9PuxsCgCAlhxuGhp6JWlBfyH0YFBWLAKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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