SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91c32a2b67bff039a665ed27c283abc8ac18e787839e895fcfc8ddd33729eb02' 
  AND token = 'V7jufNJEeStUTrc4Lu9pbqfiI4uYuKt/V9T9Plr7rVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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