SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c85b586cbc9b69785209b9c2a3db27f1e7f2a43cadf84f3095910705f577db7' 
  AND token = 'FJGhYX5wZPBDMVe4UgLFdWHwzxsJAGV4gVylrpokSX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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