SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7aeebb1e78c02aa93e5903c5340b0c9e3d8fdb8c8b7d55beb27b221c0fedeaa' 
  AND token = 'RMzOaBjIYlGBv5C/zEU1WrJISt42oOcwqdb81+eZuuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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