SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5392288edfdfc700d5822a07250dfed3fc2d7f65a4b5da68e4779db47789b700' 
  AND token = 'I3cI2ljWJlPbwxhQWgiJpNrrXERpCsiD3Gy8bj0jPew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}