SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f47bf291b8f3a64bf0380ac271b8eb11822d57cd86e5ea78986d8d0cdb3f0fa1' 
  AND token = 'isjoCdg4erctaJrS2HubL34ae2TGaMwSXklUS4PQ2WA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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