SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3e688a22a0a40a6cde224edbaad57d6f5d06df9c68edb3b648facd39f8e884e' 
  AND token = 'SgSJ26KWXKWjKcUdKGxWAAkzS80JlVhikTNGufoEkQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00118

JSON explain

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