SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd93ea261932f2aadcf0707060d162612d1fd34ad05a3341dd694b7706780f499' 
  AND token = '/5F8B6dJ52XnJ6kV0wMNgrHCltkKw3TcrQUMPSTYfaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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