SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0931fdbcec1f724474d6049fdf168e530fdfed6e2e2d37de31379ee3b6b7d5f' 
  AND token = 'dl0zYnM/vd5K7AlFv0bkyWFk02qMvUauHyBwrXSwveM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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