SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ad669e669bdcb89f124c245043d68cc5222954198847b7e396b041ca39adf81' 
  AND token = 'X6uesXa/cwV/LMnzBZ70h6WMNmZQFz/qP9gs+4kacEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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