SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '660440b61bc22fbaf06ef973b82a917991216a4bc3efc03b33a59b0215b26baf' 
  AND token = '0ALhHKwNzcETsoR0R7P0unTGStzdjJy8ZoIf3pvw0wk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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