SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f13768232aa862c84664ca19315b2b26e0596f74794b122472593f94de632ac' 
  AND token = 'hHtyxR4PhZpjKnPURiAtiTaUx7C408zY3KyZmw95fGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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