SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a6da468386d5bb74c955f7d1a332634974eeac14de8672918cd4d901db558ca' 
  AND token = '5HjrZ29/X3Sz++YcEtufeGZ8DfsQG83K4zfthoA9VKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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