SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d26a83c0222f41df0864f27eaca6434cb4f8c099d0831d75b61fc7c4901594b' 
  AND token = 'xoJpqbrkbuyWEJAfGNhitgwBR81Vz9x/cdfvYoApIBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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