SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5863f9ba1b8578972559cc894268f3bbf1d39661bd39bba6aa964eaee54959f6' 
  AND token = 'SuVhXtWrLH98tVVoKkOdc6wIz6z1Rg9/ZOzbTkJt6Ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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