SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cdccdb02c0655686d4a7b8273b5dcd1dd4e21ebfce9c4afa67c56e881b01a30' 
  AND token = 'kDiRXhj82t0jdzKa6HfxwtO1cjhHCS1C66VPAvXIVYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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