SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4254fc5b645bb6d35943c4c24549e6bd1079a1e7f07269070119ad9a0a2662bd' 
  AND token = 'AyVhciZaXQlE0cAXZgvHKTcCKAj0Y5v9sXa7plRI3Wg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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