SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58a797453373921edc996323c4cb7c2b50a8e192c81772cb33a2f58c6394898e' 
  AND token = 'EpOOskFl5jvUz+qMPApVlvDyWbBSMgrygZaZ/OvyjvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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