SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '812573077763209fd4c3906c9a5119d2f820782b9764b75749b7e52b9b467f19' 
  AND token = 'lhVRgqDBaTshD2RuWlkYyBOs1uho3h7Z6P0up7sUv8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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