SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5df1c58b4dd049977e150cf47027471b052ca016f429807c2d56aee22a9b8483' 
  AND token = 'Ht4H4NwAkJyEdhh66BfdA93ZfVoouLTOsOrnbGwK0OI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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