SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f0c21f99e0a9bdcad245c59c2adf38109a4dfa93aeb073ef537bd68c7d114ca' 
  AND token = 'N9EltYb8w+UM8OXX5v4wQMZPAlHgPlbgzQZ0FmqDSXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}