SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73acc82d34c9a18247ddf0272ed9081a0ea3e0e90158644ec339bcc8c7ac442d' 
  AND token = '5ewcpkACyd1Yg+UwyW7TMoeQqr+FxdZPyWqWOAL09BY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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