SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae8409aa8e0d07a43f543c195cc5138454ff769ef4974fecffd343f03b56fd53' 
  AND token = 'sPH0ndUX15YYUpJFJWIfyySPFraZpTQ20LuNFUrx3VY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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