SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0cafe15c32cb49380192bba834fdbf13a194dca848d60db8cd2bad8d5972f1f' 
  AND token = 'xbLFV2TDsMjQx+iuDX8zAK3p6uLeVZQyOw/Vpu3olYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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