SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f629c9955c9027d83556b4ebc33c5f9bfa9596777ad8168f2c1af9f1be49ff4d' 
  AND token = 'tfGVa88s+rgQpNuEZCCSXIPCYww4wzyYolyMxDKSgds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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