SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5733dacd82f55058ff85b0f36c253efc22bdd6601981996e752b44fe0b21c7ae' 
  AND token = 'RbLScyTfnE+QxBmKItrv9Iqanzuv0YMWR1haEV+z36A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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