SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6476f692381d4d0852af396def4a7e88e14f597020d9c11d2bd88b03359c4264' 
  AND token = 'o9/N1OksDJZFFyKb7OhJngh380OXnFhDiq5D+YXig1U=' 
  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"
    }
  }
}