SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b9e68e98dc19cea5d309c4ca6c8b9a0bfb15981e693090c46e3d997b97d0af5' 
  AND token = 'gL2nOdorZ+SNf8eFpytXPiKsQq6wtguQKouyq8TnD9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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