SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0ffefb30a265b82a20009822fc082c09218edebcdb174f8fcfd754cb3776748' 
  AND token = 'Hd223ETMCGDyicV29PjEkoLQbJtWM73RnpSLkiTOqAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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