SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65be2eb020f94a2b453ee69f9aedbd2440689ada714711ab5188b9e8b5ca75db' 
  AND token = 'xsJQq2KwCagrgS0dU7efBXOkUMwKUEbVC9dyTdyWeWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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