SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb95818c0437af687842235b318bbead7c0dff0d85e7f9ecfe85506feeeb071b' 
  AND token = '0SLNNYyUvavPkxdiDkh5UTC5cQxoepjSrHLG8KjkuAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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