SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a093ddc18a60b673e66ae4832756d482a4245261995ecaf3424803c40fd63a6' 
  AND token = 'kqK2g6W7WHKFqJp3AmakxjGCqRJAnhHhXDi6ZDF7/Cs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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