SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93ba1dd4f7840d1ebe483f350b541f1d26b51f0de01e59dcbee599b759d5a9be' 
  AND token = 'ljgquy9SUJQiiT0Ciqea3kqKrkwvvUTEpCS0rnMHahk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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