SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '668b21a27a4e0598562c6f514092e7714131b566b9089628803d0722200253a2' 
  AND token = 'LRFU0VJ90TmYJm8Mu5hToVUtH90YtyLDj9bt/CfwW54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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