SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '468286d3574834a73c83c961b295a6fd23a04b0272f65bc03b39ef3f791a6902' 
  AND token = 'C0QaxiRctY4bKWqZuo09wNt/28HjOzhqnp4/Yefuhyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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