SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '155fff4100b73cc2b39dfc02dcf53560915b40178d398be77d7ef7a4cd727cb9' 
  AND token = 'mt5dBFKSjKeO3g/F4atYq17WsXDmaOFX0mmfslCU1xY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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