SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8fa80c870632eb9d83fde293d172bf86ab893a69c9d423bceed367aadf1650b4' 
  AND token = 'MZh7DnR+b2rW783clY9mfpI6d3Y+TU79kDUToYW6cwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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