SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32073048902241996587610c677407672cb4e966af9f875077874125717e94c4' 
  AND token = 'KLv3j+qm8yuAtUIjcYcQTuE6GlQGa16vGOGdTWD9QnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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