SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '35af72677c6da555b331e17a8c115a7f9d57475588817d5ebb1ea3ed468454bc' 
  AND token = 'rUUgmw96kkBx79AqCtMeNumiT+jnWi8+lcWe3U6AxgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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