SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '430583cc9cbd415aed0b1ac410b4b8b8b60c6a3e172f217308ec1fd296f745d7' 
  AND token = 'hGhls3eEVKX2yWvtMRaCDhKwZFbcgnVdLlix0O8IlW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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