SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4839dde508f4f77188c95547c8f71169e598e146f78b095b028e798ae5df445d' 
  AND token = 'wM3beeKgF/cGG4oICRqzBzzwGPJCHEIB5kaD3+g7o3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00070

JSON explain

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