SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '280af5ac017a50ea94c7291508b0e1ee0a3d2bcbc8c5a9d2bc9360d7d155a3e6' 
  AND token = 'SfK/iu+JTzz2Cop85gQD7gm0BspXwjVw9lf4QNAx/0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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