SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf2f2a587fc281fca2e8a36d796835f7c18dd354f15ef972d8d471b25f0fd1da' 
  AND token = 'fUiMh6MdAiG8hXlIToyRUpqvT9ctFH078IxmqbNKH3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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