SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed58e6b856b95b47376ec1ace828f91ba491aabd5cdcf96caa53069bf3686819' 
  AND token = '3IiFFPWbu80HRfY7kpBoPBXdCIf5v9OvwQGhatEsuFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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