SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44ed93340e7fc409a31826e2d467a528d5784b5927fe2727fd20afd44f5f5737' 
  AND token = 'ALDL1QsFg5Q0EOhoHbdhm2AjjNgje8freHW+PdhYiVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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