SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af06b7a6958143105bbced63044111c6a3d97bc50f55c2a653cd81ebdeab6010' 
  AND token = 'sN+QMBeK7Q3c2S8/vcdIlnYhY6LHUQmIUs4tv9RH5WU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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