SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '87fc79e51a3392cdc18a91016860c33f7f824b19cb1e3441d827361968fe9d5c' 
  AND token = 'eNKgB2E33zvubDn+n1DbWpRlmErvRNyWfoqtjXK3d0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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