SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac91c8d54b43d1225d2b67415820ea5b1eb1700846be9c6ebe9eeada8d89490e' 
  AND token = 'pGECbTEBa2IipmHgBebfELmTZ6J1O56nYs81IWznm9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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