SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b7779be67941414ce418bf19d935c857719e42646456fdbfb46c7f6ca80c2f43' 
  AND token = 'kPnAwrAM7BLFRWxZa38ma1WBYaRnkFzfPpvNlappoHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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