SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45ba6fc64f3811c0b188b687064e08a0f3c99b60eaa7fa0c1b673979e87057e2' 
  AND token = 'uj8PzCHzOdya51HidOw3wcHcSYz/2YvRHObz6gm3ES8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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