SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff5fa72e824d11ddd677be62c390503a5e2ad43d7f62a581ba21d38e8d55a490' 
  AND token = 'NOBqjW7WvC1kcTJF+OmfxFIT4zezMX0JEhobXVszd3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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