SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '101839c4f10ec3f4228ba55ad40a8404040581e00914b81ba25dd83b260ee1f5' 
  AND token = 'MLWMazjJj/UGpkcyukuRIZAD18NwhHlMyRwXhR+3w3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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