SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '664cbacbafb8b22a0e8fbfb4c2bf03cf06593f0d05ac771f5d5def4e04a93c4f' 
  AND token = 'iVeNCxc0i/fAZRv2zFu/zpUvtKp97eQhLjFXfj/ojAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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