SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41997b2742aa2f7d11a4bc912160d75aada0d64c3e03df2df92bb8ea727bfb7d' 
  AND token = 'eiiOG/uhz2ZMPLqPW9eCF3kqxtNUOFdbQ2ziYQiyFH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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