SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd4f9e021c7792a1742e5d2bd5ddca68d75ecad1046a8cec0d98d4b6054808dd1' 
  AND token = 'P7ZtejL3K80ES7I39i4/GjyVXA7bqHgyrKVtmsfy9lw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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