SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '00260e3196f5b4f7997e16344b9453802fad84ee84f7b17e9d74275885b67df0' 
  AND token = 'v6ETJi+CQCeXo/CAQwusxMNsVS+ASLrFlpVpbs1Y+BA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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