SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57772c00e99671133c4e3de9eaaf51826cec28e78c4d44017378180cf65f9843' 
  AND token = 'rUFVVqD1SLnSduROCkhI+wv5unATCOWBjmzGIkO03p8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00083

JSON explain

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