SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44994bb7ddd037d4fd3fe88337f7fbe18f9e8bbabd460a654ebc5818f094322d' 
  AND token = 'ToL76RTWPtOlrx1/Vd9crbIdxscNnptj9AOfCJJZTxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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