SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10b241dea7f160a4b670b950e139e395d5bc706dce3f3d2f2cf357282fe4ae71' 
  AND token = 'M2d97qvMVW6iHaPwRwXQ8S2btN8x64HZBTmBs1A0GSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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