SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f7516119f0b8fdb8afd804eab763d470abe85704c08f1131268d57a7df69926' 
  AND token = 'X8LHrv79s7/6DJ99DBfeRVq5sHtKrIh6UOJFEdrC6WE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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