SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25522bd483308d322afae51f1f3d003b4139b103485cfbdfb88b1cdc725afe81' 
  AND token = 'u5upsc3mdeAYXXPTLXzGdFlCzwNGRzy6FiswTcu+H8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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