SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd6c91577321a4a4bebb2f0d0e80723f375f1eb77dc42b36c75999fea287dd08' 
  AND token = 'PmfSkBBkRmwWxF50xcUonr/yf9ys8Sg/6r78/VFzS7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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