SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37b423855bc7fd59918bb46728228e716bba526693b8bef76df16ac570054510' 
  AND token = 'x7nJXpY/8A2VQ+ETltyiNTlPtz7JUwzPgdBXYZfDj3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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