SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d4fcc4a509a56f8a58fdfa8468aa82e11410a22371bc70bb5bbad7fb687060f' 
  AND token = 'D+OQpMYkc/2D2ckIpJU+uHwqPvKPO/bwrr/gBG3bwS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}