SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4818c0ec0825904b1ba6f3db314399608dd264627798ed6e731ff6149f3f7621' 
  AND token = 'tGFv7h/JdXM9kRUSCezU5nq0a5aj1ZIvxwzkVZxMTwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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