SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0ab10cb5c35db472575d54b4701b14eecd8d81c832d5d29af36dde53485b1a58' 
  AND token = 'uabLFRM6MU/mmcLYHye7KX/Xe4NKm+9SunfHO7M+drs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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