SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5dc67b0df828bec4b9b06aae45e1a7f8fb5ed1d9765d0a05a05fc4da0041d2ef' 
  AND token = 'PFWOUT+BIuYE8oTj4OZ/TYwpBFJ+uqWXvtR/Zglnj2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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